js falsey values code example

Example 1: javascript falsy values

the number 0
the BigInt 0n
the keyword null
the keyword undefined
the boolean false
the number NaN
the empty string "" (equivalent to '' or ``)

Example 2: javascript falsy

// Falsy values:
0
''
undefined
null
NaN

Example 3: is null falsy javascript

/*
	Yes.
    Full list of falsy values:
    Anything evaluated to be 0
    '', "", or ``
    null
    undefined
    NaN
    Obviously false
    Big integers relative to 0n
    -------------------------------------------------------------------------
    To clarify, line 31 will print false.
*/
var someCheckIsTrue = false;
const checks = [
  0,
  '',
  "",
  ``,
  null,
  undefined,
  NaN,
  false,
  0n
];
for (const check of checks) {
  if (check) {
    someCheckIsTrue = true;
  }
}
console.log(someCheckIsTrue);

Example 4: javascript falsy values

if (true)
if ({})
if ([])
if (42)
if ("0")
if ("false")
if (new Date())
if (-42)
if (12n)
if (3.14)
if (-3.14)
if (Infinity)
if (-Infinity)